Machining slots, particularly blade retention slots, using SAM (Super Abrasive Machining) or wire EDM (Electrical Discharge Machining) often times results in the creation of unwanted material upon the machined surface. In particular, SAM tends to produce undesirable, thin (approximately 0.0001 inch) localized areas consisting of white layer and bent grains. Similarly, wire EDM tends to produce an undesirable thin (approximately 0.0001 inch) uniform layer of recast material along the surface cut.
As white layer and recast material is generally unwanted and may have an unacceptable deleterious effect on the operation
As white layer and recast material is generally unwanted and may have an unacceptable deleterious effect on the operation of parts such as blade retention slots, it is desirable to precisely and uniformly remove a thin (up to approximately 0.0005 inch) layer so as to remove all of the white layer and/or recast material. Once such white layer and/or recast material is removed, the disk slots may optionally then be conventionally shot peened to provide desirable compressive stresses. Unfortunately, SAM or EDM re-machining would produce the same metallurgical damage as described above.
What is therefore needed is a method for removing small amounts of material from the working surfaces of blade retention slots, so as to precisely and uniformly remove undesirable layers of white layer or recast material. Such method must be able to precisely and uniformly remove a thin layer of approximately 0.0005 inches from the inner surface of a slot.